Simultaneously twisting and interlacing a continuous multifilament yarn



Nov. 3, 1970 BERG ETAL 3,537,248 SIMULTANEOUSLY TWISTING AND INTERLACING A CONTINUOUS MULTIVFTIILAMENT YARN Filed June14, 1968 2 Sheets-Sheet 1 IINVENTORS: ERNST BERG PETER HUSSLEIN PE ER HEINEN JOSEF RONG EN ATT'YS Nov. 3, 1970.

Filed Junelg, 1968 FIG; 3'

SIMULTANEOUSLY TWISTING AND INTERLACING.

A CONTINUOUS MULTIFILAMENT YARN E. BERG Fl AL 2 Shets-Sheet 2 mvENT'dRs: ERNST BERG PETER HUSSLEIN PE ER HEINEN JOSEF RONG EN ATT'YS United States Patent 3 537 248 SIMULTANEOUSLY T WIS TING AND INTERLAC- ING A CONTINUOUS MULTIFILAMENT YARN Ernst Berg, Elsenfeld, Peter Husslein, Meehenhard, Peter Heinen, Oberbruch, and Josef Rongen, Karken, Germany, assignors to Glanzstolf AG., Wuppertal, Germany Filed June 14, 1968, Ser. No. 737,188 Claims priority, application Glermany, June 19, 1967, G ,4 3 Int. Cl. D01h 1/02 US. C]. 57-34 18 Claims ABSTRACT OF THE DISCLOSURE A process in which a continuous multifilament yarn is simultaneously twisted and interlaced by treatment of the yarn with a fluid jet which intersects the yarn as it is guided in a substantially linear path and then directly conducting the yarn into a rotating balloon pattern which imparts a slight twist to the yarn at approximately the same point of the interlacing or fluid jet treatment. Apparatus for this purpose essentially includes, in combination, a ring twist twisting spindle and means for said fluid jet treatment positioned as a yarn guide at the balloon point of the balloon pattern produced by the ring twist twisting spindle.

This invention is concerned with a process and apparatus capable of simultaneously twisting and interlacing or texturizing a continuous multifilament yarn, and more particularly the invention is directed to a method and a novel combination of apparatus which produces a relatively smooth surfaced and highly cohesive interlaced yarn under conditions which avoids damage to individual filaments and provides a yarn of uniformly high quality and good textile properties.

In order to properly handle a continuous multifilament yarn, e.g., composed of the usual synthetic thermoplastic filaments, after the initial spinning and stretching steps, it is a general and often necessary practice to subject the individual filaments to some kind of treatment which imparts a certain degree of interlacing or entanglement such that the filaments become more coherent as well as exhibiting a more texturized effect. In some instances, this has been achieved by an expensive and time-consuming crimping process in which the physical structure of the synthetic filaments is permanently altered to provide uniform or random bends, arcs or loops in the otherwise normally smooth and linear filaments. In addition to the time required to impart such crimping to the filaments and to permanently set the crimp, the individual filaments are often weakened or damaged or the resulting yarn may tend to lose its coherence during subsequent textile operations.

As an alternative to such crimping processes or as an adjunctive treatment with only moderately crimped yarns, two different procedures have been suggested for the purpose of achieving a cohesive yarn structure. In one procedure most commonly followed, the yarn is twisted so as to bring the individual filaments in close contact with one another. When employing such twisting as a means of obtaining a cohesive yarn, especially when working with fully synthetic yarns, it has been proven necessary to employ a first twisting immediately after the freshly spun filaments have been stretched to achieve their essential strength and other desirable textile properties, and then to employ a second twisting subsequent to the first twisting process.

The other procedure for achieving a cohesive yarn structure is to subject the initially spun and stretched 3,537,248 Patented Nov. 3, 1970 filaments of the yarn to the turbulent action of a fluid jet stream, usually air, in a suitable blowing or blast device. The individual filaments are thereby interlaced or securely closed upon one another at more or less irregular intervals along the length of the yarn. This blast or turbulent jet treatment of the yarn is often carried out under such extreme conditions as to produce a voluminous or bulky yarn containing a large number of loops or ring-like convolutions in the individual filaments, sometimes referred to as crunodal loops or under conditions which even cause breakage of individual filaments so that loose ends project radially outwardly from the yarn structure. While this extreme texturization of the yarn is useful in producing bulky yarns exhibiting special properties, it is not satisfactory for purposes of the present invention wherein the desired interlacing effect is intended to produce a relatively smooth-surfaced yarn which is substantially free of projecting crunodal loops or broken ends of individual filaments.

Thus, where the cohesion of the yarn filaments is to be achieved by the action of a fluid jet medium without substantially reducing the strength or otherwise injuring the uniform textile properties of the individual filaments, a compromise is necessary with reference to the so-called mean gap length which is a standard measurement for determining the extent to which interlacing has been accomplished. For the purpose of achieving small gap lengths, it is necessary to employ relatively high air pressures with a correspondingly high velocity of the fluid jet and a high consumption of air. The use of the air or other gaseous medium at lower and more economical ranges of pressure and velocity generally leads to much larger gap lengths which at best fall within the very upper limit at which cohesion, if any, can be ensured.

In addition, it has been proven that the individual filaments are very severely strained in the use of a highly intensified fluid jet action so as to impair the strength of the treated yarn. Moreover, since the damage to the filaments is strongly dependent upon the surface roughness of the thread guide passage or channel of the blast device, it becomes quite important to maintain this thread guide passage as smooth as possible. However, when subjecting the yarn to a fluid jet medium such as a highly compressed gas which emerges from the jet nozzle at a velocity in the region of the critical velocity of the gas in a cylindrical passageway, the strain exerted on the guide passage receiving the yarn is extremely high and the wear or abrasion of the guide passage surfaces is correspondingly severe.

It has thus been extremely diflicult if not practically impossible to use the fluid jet treatment of a continuous multifilament yarn for the purpose of producing a relatively smooth-surfaced but adequately interlaced yarn having good filament cohesion. At low pressures and velocities of the jet, the gap lengths in the yarn are too high to provide adequate cohesion, whereas at high pressures and velocities of the jet, an undesirable bulking effect occurs with a correspondingly high degree of filament damage, reduction of yarn strength and undue wear on the yarn guiding surfaces.

One object of the present invention is to provide a novel process and apparatus capable of simultaneously twisting and interlacing the individual filaments of a yarn in order to produce a smooth-surfaced highly coherent yarn structure, thereby avoiding the disadvantages inherent in the use of either twisting or interlacing by a fluid jet treatment alone.

Another object of the invention is to provide a very economical process using conventional apparatus in a novel combination capable of yielding the desired interlaced and cohesive yarn which retains highly desirable textile properties of strength and which is essentially free of so-called crunodal loops other than extremely small loops or ring-like variations of microscopic size.

These and other objects and advantages of the invention will become more apparent upon consideration of the following detailed disclosure of the invention.

It has now been found, in accordance with the invention, that a cohesive, smooth-surfaced continuous multifilament yarn of highly uniform and desirable textile properties can be produced in a surprisingly satisfactory manner if the yarn is drawn in a guided substantially linear path through a single turbulent zone into which a fluid jet stream is directed for lateral intersection of the yarn path at a velocity sufficient to cause interlacing of the individual filaments of the yarn, and if the yarn is then conducted as it emerges from the turbulent or fluid jet zone directly into a rotating balloon pattern which imparts a twist to the yarn at approximately the same point at which the interlacing takes place. In order to produce a smooth surfaced yarn with a minimum of bulking, it is generally essential to draw the yarn through the turbulent or fluid jet zone under a relatively small tension of at least about 0.01 up to about 0.2 gram/denier and preferably about 0.05 to 0.15 gram/ denier.

In general, the amount of twist imparted to the yarn at the point of interlacing and the intensity of the fluid jet treatment depends upon the particular type and denier of the individual filaments in the multifilament yarn. Surprisingly, however, one achieves an excellent cohesion of most yarns including those of extremely fine individual denier by imparting a twist of only about to turns per meter and by interlacing so as to achieve a relative large mean gap space on the order of 8 to 12 cm. By choosing a suitable fluid jet nozzle or blast device, the absolute pressure of the flowing gas such as air can be easily maintained within limits of approximately 2 to 2.5 atmospheres (corresponding to a gauge pressure of 1 to 1.5 atmospheres), thereby preventing practically any and all damaging action of the fluid jet on the individual filaments of the yarn.

The process and apparatus of the invention are applicable to a wide range of synthetic or artificial polymeric filaments, threads or yarns as obtained by conventional spinning and stretching processes, including by way of example such materials as nylon (polyhexamethylene adipate or polycaprolactam), polyesters such as polyethylene terephthalate, cellulosic filaments such as viscose rayon, and the like. Where cohesion of the yarn structure still repersents a significant problem, the invention is of course applicable to blends of such synthetic filaments with each other or with natural filaments or fibers.

When treating very fine denier yarns and especially when working with easily damagable filaments, e.g., viscose threads or yarns, the absolute pressure of the fluid jet medium generally should not exceed about 3.2 to 3.5 atmospheres. With very heavy denier yarns, e.g., rug or carpet yarns of high molecular weight synthetic polymers such as nylon 6 or nylon 66, absolute pressures of more than 5 up to a maximum of about 5.5 atmospheres can be tolerated. For most purposes, good results are achieved in a range of absolute pressure of about 2 to 4.5 atmospheres, preferably about 2.1 to 3.5 atmospheres.

The amount of twist is likewise dependent upon the size or denier, sometimes referred to as the titer, of the yarn being treated. In general, the number of turns falls in a range of approximately 5 to 40 turns per meter, preferably about 8 to 20 turns per meter, the number of turns decreasing with an increasing titer. In no instance will the twist exceed turns per meter since there is only a trivial improvement achieved at this point, and at a significantly higher amount of twist, one would be working with a relatively highly twisted yarn without any substantial interlacing;

The process of the invention thus requires a careful balancing of the interlacing and twisting treatment of the continuous multifilament yarn, and it is therefore desirable to treat a substantially untwisted yarn, e.g., as obtained directly from the initial spinning and stretching steps of a conventional process for the production of synthetic or artificially regenerated filaments. Some slight pretwisting can be tolerated, e.g., up to approximately 5 turns per meter for relatively fine denier yarns, but it also is preferable to work with relatively straight or linear untwisted and noncrimped filaments.

Most importantly, both the interlacing efiect achieved by the fluid jet treatment of the yarn and the twisting efiect imparted by the rotating balloon pattern of the yarn must be carried out simultaneously, i.e., the so-called balloon point must coincide or be located in the immediate vicinity of the point of action of the fluid jet medium, i.e., in or directly adjacent to the turbulent interlacing zone. Satisfactory results cannot be achieved if the yarn is pretwisted before the fluid jet treatment, and it is not sufficient to first interlace the filaments and then twist the yarn at some subsequent or removed point in the overall process. Furthermore, a small but essential tension of about 0.01 to 0.2 gram/denier must be placed on the yarn during the specified simultaneous interlacing and twisting treatment if one is to avoid undue bulking and the formation of visible loops, convolutions, snarls or the like which may further reduce the mean gap length to undesirably low values as well as possibly causing damage to the yarn, especially during subsequent textile operations.

It is a particular advantage of the present invention that the simultaneous twisting and interlacing treatments can be easily adjusted within relatively broad limits and readily adapted to a wide variety of yarns without running the risk of damaging the yarn or causing the yarn product to lose strength or become nonuniform in its quality over an entire run. The best conditions for each particular yarn can be readily determined by a few simple preliminary tests or by simply adjusting the pressure of the fluid jet and the turning rate of the balloon pattern during the initial stages of the yarn treatment.

The term mean gap length is employed herein with reference to a conventional means of measuring the amount of interlacing or entanglement achieved during the fluid jet or turbulent treatment of the yarn. This measurement specifies the gap distance over which a needle or pin inserted into the yarn perpendicularly to or radially of the yarn axis can be moved longitudinally up to the point at which the fiber entanglement collects or dams up in front of the needle so as to prevent any further relative movement between the needle and the yarn.

The term balloon point has its common meaning as applied to the so-called balloon pattern created by a ring twist twisting device in which a yarn or thread is applied to a take-up spindle as it travels from a guide point lying approximately on the extended axis of the spindle or bobbin to a ring traveller which rides on a ring rail circumscribing the spindle or bobbin. Between the guide point located axially of the spindle and the circular movement of the ring traveller, the yarn or thread is caused to rotate around the end of the spindle or bobbin to generate the so-called balloon pattern which in turn imports a twist to the yarn. The linear tension placed on the yarn as it passes through the balloon pattern can be easily regulated with conventional ring twist twisting devices.

The values of absolute pressure mentioned herein are measured at standard conditions as sometimes designated by the abbreviation S.T.P. referring to standard temperature and pressure. The gauge pressure of course refers to the amount of pressure in excess of one atmosphere as measured by a manometer or other suitable pressure measuring device which can be readily used in conjunction with the fluid medium such as air or other gases which are maintained under compression in the production of a fluid jet through a suitable bore or nozzle in the blast device.

The apparatus of the invention, while generally including the conventional means for transporting, stretching or otherwise subjecting the yarn to conventional preliminary steps, essentially resides in the combination of (a) a ring twist twisting spindle having means to receive a continuous length of yarn while imparting a twist thereto as the yarn is conducted through a rotating balloon pattern, with (b) means located at the balloon point including a yarn guide means together with means for treating the yarn with a fluid jet arranged to laterally intersect the yarn during its passage through the guide means, preferably so as to produce a turbulent zone in which the individual filaments of the yarn become interlaced. A nozzle for the fluid jet is preferably arranged perpendicularly to the linear path of travel of the yarn which in turn is preferably conducted through a substantially cylindrical elongated guide channel. The best results are generally achieved with a fluid jet treating device having a single turbulent zone with the jet nozzle entering at one side of the tread channel with the axis of the nozzle positioned to intersect or at most be displaced about 15% from the axis of the thread channel with reference to the diameter of the channel. The axis of the jet nozzle may also be inclined at an angle of up to about 30 from the perpendicular with reference to the channel axis provided that this inclined position directs the jet stream in a direction opposite to the direction in which the yarn travels. A number of preferred embodiments of the fluid jet treating means are set forth hereinbelorw.

The particular combination of apparatus required for purposes of the present invention as well as a number of useful blast devices or means for interlacing the yarn are illustrated in the accompanying drawings in which:

FIG. 1 is a partially schematic diagram illustrating the overall treatment of the yarn including the apparatus required for the particular combination of the present invention;

. FIG. 2 is a side elevational view, partly in crosssection, of an especially useful embodiment of a blast device or means for the fluid jet treatment of the yarn;

FIG. 3 is a top cross-sectional view of another embodiment of a blast device having been provided with two closely adjacent but eccentrically offset jet nozzles;

FIG. 4 is a side elevational view of the same blast device shown in FIG. 3; and

FIGS. 5-8 provide side elevational views, taken in cross-section, of a number of other embodiments of blast devices capable of being used for the fluid jet treatment of the yarn in accordance with the invention.

Referring first to FIG. 1 of the drawings, the initially spun and unstretched yarn or thread 1 which can be temporarily stored on the feed bobbin 2 is drawn off this bobbin and conducted through a conventional thread brake 3, e.g., a series of staggered guide pins or rods which are adjustable for regulation of the thread tension. The yarn is then stretched as it is conducted over the godet 4, the stretch pin 5 and around the draw means or stretching godet 6. All of these steps are quite conventional and simply serve to produce the required stretch of the initial filaments in order to achieve certain desirable textile properties of strength, elongation and the like.

After the yarn has been stretched, it is drawn through the blast device or turbulent zone of the fluid jet treatment apparatus 7 which in this case corresponds to the device illustrated in greater detail in FIG. 2. From this blast device, the thread is immediately conducted through the balloon pattern 8 as it passes through the usual ring traveller mounted to slide around the ring rail 9 of the ring twist twisting spindle 10, the yarn being collected in the form of a biconical bobbin package 11 on the spindle 12 which can be positively driven or rotated by conventional motor drive means (not shown). The ring rail 9 travels axially back and forth along the spindle at a predetermined rate so at to properly wind the yarn package, and the so-called yarn balloon 8 may of course have a more pronounced arcuate shape than that actually shown in the drawing.

The rate at which the yarn rotates around the spindle in its balloon pattern 8 is dependent upon the twist spindle turning rate so that the amount of twist being imparted to the yarn at this point is easily regulated and lies within the range commonly employed as turning rates of twist spindles. The twist of the yarn is normally generated or quickly transmitted to the so-called balloon point which is ordinarily a simple thread guide ring located axially above the twist spindle. In the present invention, however, the function of the thread guide at the balloon point is assumed by the thread guide passage or channel of the blast device 7, so that the twist imparted by the ring twist twisting spindle and the interlacing effect of the fluid jet stream occur virtually at the same time and at the same place, i.e., within or immediately adjacent to the turbulent zone created by the fluid jet. Furthermore, the rotating balloon pattern of the yarn causes it to constantly rotate or turn along the inner wall of the yarn channel in the fluid jet device 7 and at the same time the yarn is constantly struck by or subjected to the turbulent action of the jet along different portions or layers of its surface and cross-section, especially where the yarn channel or passageway is somewhat larger than the yarn itself.

The particular fluid jet device 7 disclosed in FIGS. ,1 and 2 is constructed in a manner which has been described in detail in copending application Ser. No. 699,392, filed Jan. 22, 1968, the disclosure of which is incorporated herein by reference in order to avoid a further detailed explanation. Briefly, this device includes a fixed supporting frame 13 on which there is rigidly mounted a polished tubular member 14 serving as a pivot for the swinging or rotatable arm 15. The hollow tube 14 also provides a feed bore 16 as a means of supplying the air or other gas to the jet device. This bore 16 is in fluid connection with the perpendicularly aligned bore 17 in the swinging arm 15 when this arm lies against the arresting pin 18. Toward the end of the swinging arm 15, there is removably mounted a block 19 having one passage 20 coaxial with the bore 17 and extending through the block to form a resonance chamber 21, a second passage or channel 22 being bored through the block perpendicularly to the jet passage 20 as a yarn guide and means of positioning the yarn for the turbulent jet action. The threaded plug 23 closes off the resonance chamber 21 and at the same time serves to securely fix the block 19 in place in the arm 15. This block 19 is preferably made of a highly wear resistant material capable of providing a smooth guide channel 22 for the yarn.

As shown in FIG. 1, the fluid jet device is preferably arranged in its engaged position, i.e., when the swinging arm 15 lies against the pin 18, such that the axis 24 of the yarn guide channel 22 coincides with the axis of the spindle 12. In this engaged position, the passageway for the fluid jet stream 17 and 20, including the resonance chamber 21, is connected with the feed bore 16 through the lateral opening 16' in the tubular member 14. With the compressed gas turned on, the fluid jet device is placed in operation with bores 17 and 20 acting as a nozzle for the fluid jet stream and the resonance chamber 21 creating a desirable turbulent zone in the yarn guide channel 22 where the yarn is interlaced.

In order to stop the jet treatment, it is possible to simply swing the arm 15 to the off position as indicated by the broken line representation 25 of the device in FIG. 2. The compressed air or other gas is blocked off as the bore 17 in arm 15 slides away from the opening 16 and rests on the smooth outer surface of the tubular member 14. The yarn 1 is strongly deflected by the upward movement of the arm 15, and if desired, the yarn can be broken by a rapid or sharp movement of the yarn, thereby effectively shutting down the entire operation.

Another suitable fluid jet device is shown in FIGS. 3 and 4, wherein the block 26 contains the yarn guide bore or channel 27. Two jet or blast nozzles 28 and 29 enter tangentially at right angles into the guide bore 27 and have a substantially smaller diameter than the guide bore. Since the two jet nozzles are displaced on opposite sides of the axis of the guide bore, the jet streams enter into the guide bore so as to flow in opposite directions around the inner wall surfaces of the guide bore. This high velocity countercurrent flow acts so as to produce essentially only one turbulent zone capable of interlacing the yarn filaments. It is preferable to offset the jet nozzles 28 and 29 in the longitudinal direction of the guide bore 27 at an interval between their axes of up to 3, preferably about 1 to 2, nozzle diameters. Also, it has proven to be especially effective in using this type of fluid jet device for purposes of the present invention if the direction of the jet stream closest to the outlet of the yarn guide bore generates a turning movement of the yarn opposite to the turning direction of the rotating balloon. Further details concerning the specific device illustrated in FIGS. 3 and 4 can be found in Spanish Pat. No. 241,594, particularly with reference to FIG. 22 thereof.

Another especially useful fluid jet device is shown in FIG. 5, where the construction of the block is similar to that of FIG. 2 except that the yarn guide channel 30 tapers or narrows conically inwardly from the yarn inlet side in the direction of the yarn travel until it meets the fluid jet bore 31 which extends into the resonance chamber 32 at the point of incidence 33. With this device, it was previously found that certain improvements could be achieved in the interlacing effect and especially in obtaining better dyeing properties of the yarn by arranging two pins 34 and 34' immediately before the yarn inlet, both pins being set parallel and close to one another and perpendicular to the linear running path of the yarn. For purposes of the present invention, these two pins can also serve as a means of more carefullyregulating the tension placed on the yarn during its treatment by the fluid jet. This particular device is also explained in greater detail in copending application Ser. No. 699,392.

, The fluid jet device illustrated in FIG. 6 corresponds to that which is disclosed in Canadian Pat. No. 554,150 and can be used for purposes of the present invention although it is not quite as effective as the other embodiments illustrated herein. In this case, two separate blocks 35 and 36, prefaably cylindrical in shape, are spaced at a slight interval from each other, such that their oppositely disposed faces in the form of the planar surface of a truncated cone provide a nozzle outlet for the fluid jet stream conducted through bore 37 in block 35 and a resonance bore 38 in block 36. The bores 37 and 38 are coaxial and lead to the formation of a turbulent zone or blast point in the space between the two blocks. Directly above and below this turbulent zone and immediately adjacent the nozzle and resonating blocks, two ring-shaped yarn guides 39 and 40 are fastened in place so that the yarn remains centered in the fluid jet stream. Since the yarn guides do not longitudinally enclose the yarn during the jet treatment, the interlacing effect is more difficult to control and the amount of turbulence is generally less than can be created with an at least partly enclosed guide 7 channel.

FIGS. 7 and 8 also represent especially preferred embodiments of the fluid jet or blast device and are likewise explained in detail in copending application Ser. No. 699,- 392. In FIG. 7, the device likewise has a preferably cylindrical yarn channel 41 with a cylindrical jet bore 42 and its coaxial resonating bore 43 with their common axis laterally intersecting the axis of the yarn guide channel.

In this case, however, the bore of the jet and resonating 75 chamber is inclined at an angle from the more usual perpendicular position with reference to the yarn guide channel, the angle 0 being less than 90 but greater than 60, preferably about 60 to The best effect occurs if the velocity component of the fluid jet stream lying in the axis of the yarn guide channel is directed opposite to the direction of the yarn travel. In other words, the jet bore 42 should ordinarily cause the fluid jet stream to be introduced into the yarn guide channel so as to oppose the running direction of the thread. The dimensions of this device otherwise correspond to those of the device in FIG. 2.

As a slightly different modification of the device shown in FIG. 7, it is also feasible to incline the fluid jet bore in the opposite direction so that one velocity component of the jet stream runs in the same direction in which the thread travels, the angle between the axis of the jet bore and the yarn channel again falling between 60 and In this case, however, the axes of the jet bore and the yarn guide channel as viewed in the running direction of the thread are offset up to about 15% of the yarn channel diameter. In this particular construction the passageway or channel for the yarn preferably has smoothly rounded edges at its entry and outlet openings. The diameter of the yarn channel may correspond to about 2 to 15 times the yarn diameter and its length may be approximately 5 times the yarn channel diameter. In another special execution of this structure, the yarn guide channel can be conically enlarged from the yarn entry toward the yarn outlet. A similar device is disclosed in U.S. Pat. No. 3,026,- 597.

Another especially preferred fluid jet device is that shown in FIG. 8 which is particularly distinguished by a reduced air consumption. In this instance, the inlet side of the yarn guide channel 44 in the form of a relatively wide cylindrical passageway extends up to the point of intersection with the common bore of the fluid jet inlet 45 and the resonating chamber 46. The yarn guide channel then narrows to a considerable degree over a short conically tapered section to form a cylindrical outlet side 47. This construction has an especially favorable effect, not only in reducing air consumption but also in producing shorter mean gap lengths in the interlaced yarn.

In view of the wide variety of fluid jet or blast devices capable of being used in combination with a ring twist twisting spindle in accordance with the invention, it will be understood that one skilled in the art can readily select suitable means for interlacing the individual filaments of the yarn. However, there are a number of specific features or structural characteristics of such fluid jet devices which ensure satisfactory results and which permit a more careful control in producing twisted and interlaced yarns of high and uniform quality.

More importantly, it is especially desirable to carry out the interlacing of the filaments in a single turbulent zone produced by directing the fluid jet stream laterally and preferably perpendicularly to a yarn traveling in a substantially linear path within a longitudinally enclosed and preferably cylindrical yarn guide channel, bore or passageway. The use of a resonating chamber coaxial with the bore or passageway of the inlet for the fluid jet medium is also quite desirable in producing a maximum of turbulence in a concentrated area or volume within the yarn guide channel. Thus, the devices illustrated in FIGS. 2, 5, 7 and 8 herein represent the most useful embodiments in the claimed combination of the present invention.

As an illustration of specific dimensions of the fluid jet device shown in FIGS. 1 and 2, it is desirable to select a diameter of the resonance chamber or bore 21 having a value of about 0.6 to 4 mm., preferably 1.1 to 3.0 mm. The remaining dimensions can then be represented as a multiple of this resonance chamber diameter (D,.) as follows:

Diameter of yarn channel=1.1 to 1.8, preferably 1.2 to

1.6 times D Length of yarn channel-:4 to 30, preferably 6 to 12,

times D Fluid jet bore diameter-:1 to 1.2 times D Fluid jet bore length=l.6 to 3.5, preferably 2 to 2.8

times D Distance between outlet mouth of fluid jet bore and base of resonating chamber at least 2.2, preferably about 3 to 5, times D Other preferred dimensions of this and other embodiments of the fluid jet device are set forth in considerably greater detail in copending application Ser. No. 699,392. With reference to the relative positions of the fluid jet or turbulent interlacing device and the ring twist twisting spindle employed in combination for purposes of the invention, it is advantageous to choose a spacing between the jet nozzle or fluid jet device serving as the yarn balloon guide and the upper edge of the cop or bobbin being wound of about 90 to 300 mm., preferably between about 120 and 250 mm. This spacing essentially corresponds to the shortest axial length of the balloon pattern during operation of the twisting spindle.

The combination of apparatus according to the invention and the specific process carried out therewith present a number of unique and surprising advantages over the separate use of either a twisting device alone or a fluid jet treatment alone or even a combined twisting and fluid jet treatment where these operations do not occur at substantially the same point in the path of the running yarn. Thus, by means of the simultaneous twisting and interlacing of the yarn in accordance with the invention by use of the fluid jet device as the yarn guide at the balloon point of the ring twist twisting spindle, the individual filaments of the yarn are closed or interlaced in a very uniform manner so as to provide an essentially smooth-surfaced yarn free of projecting crunodal loops or broken filament ends. These results are achieved at relatively low pressures of the fluid jet medium so that the individual filaments are not substantially weakened, deformed or placed under strains which would impair the strength of the finished yarn product. Also, air consumption is substantially reduced so that the process is relatively economical.

In addition, the apparatus and process of the invention are readily adapted to handle a very wide variety of continuous multifilament yarns. Thus, in general, yarns having a wide but practical range of denier can be treated so that the resulting product has only a relatively slight twist of about 5 to 40 turns per meter while the relatively mild interlacing caused by the fluid jet treatment results in a mean gap length on the order of 8-12 cm. or above, and such yarns have a highly uniform appearance and suflicient coherence to be handled in all subsequent textile operations without being damaged and without unraveling or snagging during such operations. Such results are particularly desirable where one wishes to work with a relatively compact, smooth-surfaced yarn having a highly uniform and coherent structure without any need of employing the more conventional crimping, twisting or heat setting procedures.

Furthermore, the rotary movement of the yarn caused by the balloon pattern of the ring twist twisting spindle results in a circular movement of the yarn along or around the inner walls of the yarn channel in the fluid jet device, thereby resulting in a much more uniform strain or abrasive efiect on such walls so as to substantially increase the service life of the fluid jet device. When such rotation does not take place, the yarn tends to have an abrasive contact with only a small area of the Walls of the yarn guide channel so as to produce rough edges capable of damaging the yarn even when the fluid jet device is constructed of extremely hard metals or other abrasion resistant materials.

By way of example, the following table sets forth specific dimensions of two devices for the fluid jet treat- 10 ment of the yarn having the structure illustrated in FIGS. 1 and 2 of the drawing. These devices were then used in the treatment of a yarn so as to provide some comparison of the difierences produced by different dimensions and variations in the air pressure.

The following results were achieved in a number of runs using the devices with the dimensions set forth in the preceding table, the synthetic thermoplastic yarn being processed having a titer of 40/10 denier:

Device A Device B RunNo 12341234 Air pressure before nozzle, atm.

(gauge 2.0

Air consumption, mfi/hr A comparison of the mean gap lengths and the values of air consumption and pressure clearly indicates just how much the air pressure and volume can be reduced by the combination of simultaneously twisting and interlacing the yarn according to the invention. This is of particular importance since it has been proven that the strength of the yarn already exhibits a noticeable deterioration when working with air pressures in the range of about 3 to 3.5 atmospheres (gauge). Thus, the use of higher air pressures alone to reduce the mean gap length and achieve a more coherent yarn is not successful because of the accompanying impairment of the textile properties of the yarn. By using the particular process of this invention, short gap lengths are no longer essential since a remarkably good coherence of the filaments is achieved at a mean gap length of more than 5 cm., e.g., in a preferred range of about 8-12 cm.

The invention is further illustrated by the following examples in which the data is summarized in tabular form.

EXAMPLE 1 Using Device B as described above, there was processed a polyethylene terephthalate yarn having a titer of 68/24 denier, using the apparatus as illustrated in FIGS. 1 and 2 Draw rate from feed spool-550 m./ min.

Stretching ratiol 23.04.

Twist spindle turning rate-8300 rev./ min.

Ring traveller- No. 28.

Air pressure before the nozzle-1.8 atm. (gauge).

Yarn tension before the nozzle67 grams=0.09-0.10

g/ denier.

Cop weight-1050 grams.

Gap lengths7-l2 cm.

EXAMPLE 2 Using Device A as described above, there was processed a mixed or blended yarn of glossy viscose rayon having a titer of /24 and a glossy nylon 6 having a titer of 45/9, again using the apparatus as illustrated in FIGS. 1 and 2.

Draw rate from feed spool235 m./min.

Spindle turning rate6300 rev./ min.

Ring travellerNo. 28.

Air pressure before the nozzle-1.7 atm. (gauge).

Yarn tension before the nozzle1l.S grams: 0.07 g/ denier.

Cop weight-1000 grams.

Gap lengths-8.4 cm. mean length, 5cm. minimum, 14

cm. maximum.

. 11 The invention is hereby claimed as follows: 1. A process for the production of a simultaneously twisted and interlaced multifilament yarn which comprises: drawing said yarnin a guided substantially linear path under a tension of approximately 0.01 to 0.2 gram/ denier through a single turbulent zone of an elongated and at least partly enclosed yarn guide channel of substantially circular cross-section into which a fluid jet stream is directed at a pressure of about 2.0 atmospheres up to about 4.5 atmospheres for lateral intersection of the yarn path by the jet stream at a velocity sufiicient to cause interlacing of the individual filaments of said yarn with a resulting mean gap length in the yarn of at least cm. up to about 15 cm.; and

conducting said yarn as it emerges from said turbulent zone directly into a' rotating balloon pattern which imparts a twist to said yarn of about 5 up to approximately 40 turns per meter, the balloon point of said rotating balloon pattern substantially coinciding with said point at which said interlacing takes place.

2. A process as claimed in claim 1 wherein said yarn is drawn through said turbulent zone under a tension of about 0.05 to 0.15 gram/denier.

3. A process as claimed in claim 1 wherein the absolute pressure of the fluid medium being directed into said turbulent zone is about 2.1 to 3.5 atmospheres.

4. A process as claimed in claim 1 wherein the twist imparted to said yarn amounts to about 8 to 20 turns per meter.

5. A process as claimed in claim 4 wherein the interlacing of the yarn in the turbulent zone produces a mean gap length in the yarn of about 8 to 12 cm.

6. A process as claimed in claim' 1 wherein said yarn is composed of at least one fibrous polymer selected from the group consisting of nylon, polyethylene terephthalate and viscose rayon. i

7. A process as claimed in claim 1 wherein the yarn subjected to said simultaneous twisting and interlacing consists essentially of continuous filaments of asynthetic" or artificial fibrous polymer collected into a substantially nontwisted and noncrimped length of yarn.

8. A process as claimed in claim 1 wherein said yarn is subjected. to treatment with air assaid fluid jet stream at a velocity sufiicient to interlace the individual filaments of the yarn into a smooth-surfaced and coherent structure substatnially free of. radially projecting crunodal loops and broken filament ends.

9. The twisted and interlaced yarn product obtained by the process of claim 1. j

10. The twisted and interlaced yarn product obtained by the process of claim 8.

11. Apparatus for simultaneously twisting and interlacing a continuous multifilament yarn which comprises: a ring twist twisting spindle having means to take up a continuous length of yarn while imparting a twist thereto as the yarn is conducted through a rotating balloon pattern; yarn interlacing means located at the balloon point including an elongated and at least partly enclosed yarn gilide channel of substantially circular cross-section and having an axis which coincides with the axis of said spindle, said interlacing means further including nozzle means combined with said guide channel to provide a single turbulent zone of a fluid medium within said guide channel and arranged to inject a fluid jet stream which laterally intersects the yarn as it passes through said guide channels; and yarn tension regulating means arranged for contact with said yarn to adjust its tension as it is drawn through said guide means.

12. Apparatus as claimed in claim 11 wherein the distance between said yarn interlacing means located at said balloon point and the upper edge of the yarn package being taken up on said spindle amounts to about 90 to 300 13. Apparatus as claimed in claim 11 wherein the distance between said yarn interlacing means loacted at said balloon point and the upper edge of the yarn package being taken up on said spindle amounts to about 120 to 250 14. Apparatus as claimed in claim 11 wherein said yarn interlacing means includes an elongated yarn guide channel of circular cross-section which is longitudinally enclosed and a jet nozzle, bore extending laterally through said guide channel to provide a feed bore for the introduction of thefluid jet stream on one side of said channel and a resonating bore on the opposite side of said channel, I

said feed bore and said resonating bore being arranged on the 'same axis.

15. Apparatus as claimed in claim 14 wherein the axis of said feed bore and said resonating bore is perpendicular to and intersects the axis of said yarn guide channel.

16. Apparatus as claimed in claim 15 wherein the yarn entry portion of said guide channel up to the point at which the fluid jet intersects the yarn has a larger diameter than the remaining exit portion of said guide channel.

17. Apparatus as claimed in claim 15 wherein the yarn entry portion of said guide channel tapers conically inwardly up to the point at which it is intersected by said jet nozzle bore.

18. Apparatus as claimed in claim 11 wherein said yarn interlacing means includes a substantially cylindrical :elongated yarn guide channel arranged on the same longitudinal axis as the twisting spindle, and a fluid passageway perpendicularly intersecting said guide channel to provide means to introduce a fluid jet stream on one side of said channel, the fluid passageway continuing into the other side of said channel to provide a resonating chamber capable of creating a turbulent flow of the fluid jet stream within said channel, and means to withdraw said yarn from said channel under tension.

References Cited UNITED STATES PATENTS STANLEY N. GILREATH, Primary Examiner W. H. SCHROEDER, Assistant Examiner US. Cl. X.R. 

